What deficiency is this? Nitrogen?

Started at the lower leaves with the yellowing of the leaves, starting at the tips.

I fertilized with organic fertilizer top dressing a week ago, so I hope it starts working soon if that is the issue. If not, I guess I will have to water with some synthetic nutrients to save the plant? I was hoping I could stick to organic though, keep the soil life healthy

It's in light mix, mixed with https://plagron.com/en/hobby/products/supermix and worm castings and perlite. Haven't had to fertilize until now, so I assume the soil has run out of nutes.

Too-high nutrients can hurt your roots, which disrupts the flow of water through the plant and causes the symptom of burnt tips on leaves.

Nitrogen deficiency usually starts at the bottom of the plant with whole, older leaves going yellow and being cannibalised.

lungbutter said:

Too-high nutrients can hurt your roots, which disrupts the flow of water through the plant and causes the symptom of burnt tips on leaves.

Nitrogen deficiency usually starts at the bottom of the plant with whole, older leaves going yellow and being cannibalised.

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I don't think I have too many nutrients though. The original soil is nutrient-free, only with some mild nutrients I added. And they haven't shown any signs of nutrient burn until now, after 2 months.

It is primarily affecting the lower leaves, so I assumed a deficiency. All my other plants are in the same soil and they're not showing this deficiency yet, but they're also all younger plants, so I assume they will start showing signs in a week or two (They have been given organic nutrients a week ago as well, to avoid deficiency)

HandyGringo said:

I don't think I have too many nutrients though. The original soil is nutrient-free, only with some mild nutrients I added. And they haven't shown any signs of nutrient burn until now, after 2 months.

It is primarily affecting the lower leaves, so I assumed a deficiency. All my other plants are in the same soil and they're not showing this deficiency yet, but they're also all younger plants, so I assume they will start showing signs in a week or two (They have been given organic nutrients a week ago as well, to avoid deficiency)

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if you google some pics of N deficiency versus tip burn it should be pretty easy to tell, but its possible you could actually have both issues.

The light mix should run out of N really fast, but those mix additives can be quite hot ive found. fish mix is a useful bottled organic for the veg stage.

For what it's worth..my two cents.

That particular plant may need more nutrients than the others. N def starts at the bottom like u said. Others show no signs and your 2 months in same feed same medium. I think she's maybe a lil hungry but that top looks pretty damn healthy. I don't see any hot tips or anything near N toxicity. I'd feed her a lil more n see what happens.

I use a blank medium as well but add nothing but nutrients. Same dose seedling to harvest. I've not run into a hungry hippo yet but I'm sure I will...lol

Thanks for the input both of you. I'm pretty sure it's a deficiency. I'll water with some mild solution of synthetic nutrients while waiting for the organic top dressing to kick in. I will try to stay more on top of the organics and hope it doesn't become a real problem.

It's not just N+ cannabis is hungry for. The bunched up top could be early Phosphorus and or Calcium. Same with the chlorosis might be phosphorus.

Red Hard Head said:

It's not just N+ cannabis is hungry for. The bunched up top could be early Phosphorus and or Calcium. Same with the chlorosis might be phosphorus.

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Perhaps calcium, I'd be surprised if it was phosphorous. I've grown several years without any phosphorous in veg without any issues.

I added calmag to all my plants yesterday because some leaves on the others were showing signs of calcium deficiency (I think) I wonder how often I need to add cal mag. I honestly thought I had hard enough water to offset the need, I might be wrong!

Hard water may have calcium but the pH and other dissolved solids lock it up. A pH above 7.2 can over a season or grow be an issue.

Red Hard Head said:

Hard water may have calcium but the pH and other dissolved solids lock it up. A pH above 7.2 can over a season or grow be an issue.

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You might have just cracked the case wide open. Did two different tests, and both put me well above 7, as far as my eye can tell.

I guess I will have to start watering with ph'ed water rather than just using the garden hose. I thought, incorrectly, that growing in soil like mine would mean I didn't have to PH, but that's for some other, different soil I assume, living soil, super soil, whatever. I wonder what part of it makes it not require PH.


Any input on what my steps should be now? Do I flush the growing medium with ph'ed water?

Its the plant not the soil or water thats more dependent on pH. Cannabis is an acid loving plant really.

Yeah that pH will cause issues and lower growth and yeild.

Microbes will acidify the soil and create chelates too. To feed them use sugary water. Molasses is a decent pH down in water too.

Red Hard Head said:

Its the plant not the soil or water thats more dependent on pH. Cannabis is an acid loving plant really.

Yeah that pH will cause issues and lower growth and yeild.

Microbes will acidify the soil and create chelates too. To feed them use sugary water. Molasses is a decent pH down in water too.

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Thanks for the info and help. Do you think my issue will rectify itself if I just PH my water moving forward? I do have PH down powder. I just tested runoff from one of my plants, with ph 7 water, and the runoff was still ph 7, so I don't think the soil is fucked, only the water. (Correct me if I'm wrong)

I have well water, its hard. 7.2 when good much above that later in the season.
I rely on compost extract for 6x6x2 beds during veg. Veg ferts are also acidifiers too. Fish fertilizer will lower pH too.
When flowering i use liquid fish bone that will lower pH as well as dry ferts, phosphorus an acidifier and compost extract with molasses.
I can get pricey buying pH down, then needing a reservoir etc. No molasses used in veg for my case.
Compost and compost extract will keep soil pH near neutral on their own.
Compost extract is made fresh used immediately. 5 gal bucket 1 gallon compost in strainer bag rest water. Vigorously steep and shakes the compost in the water until the strainer bag runs clear, about 3-5 minutes. Good fert boost plus microbes and humates. Fresh worm cast or bagged work very well too. I add worm casts extract the last month to boost trichs

If you are growing in that location then the cement pavers the fabric pots are sitting on may be getting hot stressing the roots. I'd prop it up on wood and do something to shade the pot.

HandyGringo said:

Thanks for the input both of you. I'm pretty sure it's a deficiency. I'll water with some mild solution of synthetic nutrients while waiting for the organic top dressing to kick in. I will try to stay more on top of the organics and hope it doesn't become a real problem.

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When do you planning to go to flower? If its very soon, you won't have much worry about N. Your flowering nutes will take care of that.

Brycec said:

When do you planning to go to flower? If its very soon, you won't have much worry about N. Your flowering nutes will take care of that.

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It's outdoors, so I will have to wait for the end of summer before flowering starts.

However, I believe I have fixed my deficiency issues. I've started watering with water that has been PH'ed and started adding a bit of Cal mag and I think the organic top dressing nutrients have kicked in because the deficiency isn't getting worse and the plants look healthy.

Just bumping my thread because I feel like the symptoms are starting to show on new growth too. If anyone could assist me in diagnosing it I would appreciate it a ton